1. Field
The disclosure provides techniques for rendering granular media composed of arbitrary shaped grains.
2. Description of the Related Art
Rendering applications applying ray-tracing techniques construct some subset of all light paths in a scene, each light path being characterized by a set of vertices and straight-line segments connecting the vertices. A complete light path describes how light is transported, potentially through many bounces, from a light source to a viewer. When the ray of light being traced intersects scene geometry or is determined to be interacting with some particle, a new path vertex is created. At vertices, the light may be altered in its direction, in the amount of energy, and the distribution of wavelengths.
Granular media typically correspond distinct macroscopic particles (also referred to herein as “grains”), which may have arbitrary shapes. Examples of granular media include sand, rice, sugar, salt, snow, coffee, corn flakes, among others. To accurately render granular media, a very large number of light rays are typically generated and intersected with grains of the media. Paths of these light rays leading from one grain to the next, as well as complicated paths of the light rays within individual grains, need to be computed, which can be computationally expensive.